In recent years, due to the improvement of food lives and development of the medical technologies, the life spans of human beings have been prolonged and aged population has increased rapidly. It is most important for the aged to regularly exercise every day in order to maintain healthy lives for the rest of their lives. The aged persons who can move freely can do light exercises regularly while going to nearby mineral springs at daybreak every day or strolling around the villages. However, it is dangerous and difficult for the aged persons who cannot move freely due to the old ages or diseases to do exercise outdoor.
Further, for rehabilitation patients who cannot move well due to various industrial accidents, traffic accidents, or strokes, doing regular rehabilitation exercises for predetermined time periods every day are the best methods for recovering the previous heath states. Although a robot type walking exercise device that fixes a body to allow the user to do an upright walking exercise has been released, it is so high-priced to be purchased. Further, an exercise device that allows the aged or disabled or the rehabilitation patients to fix the body to the exercise device to safely do walking exercises.
The aged have functional differences due to the aging of the body functions as compared with the young. The functional differences include a body reaction time, a delay, degradation of cognitive skills, deterioration of sense of equilibrium. For this reason, the walking velocity, the step length, the walking frequency, the decrease of the joint motion range and the angular speed, and the sense of equilibrium of the aged are limited.
The abnormal walking of the aged is a main cause of hampering activities of daily living (ADL), and causes falls so that they become positive to social participation due to the fear of movement. Therefore, a walking rehabilitation of the aged is necessary to improve the quality of lift (QOL) of the aged.
In order to recover the walking functions of the aged, muscular forces should be maintained and improved through exercises. To achieve this, a suitable rehabilitation program should be established by recognizing the characteristics of the walking of the walkers, and a systematic and repetitive training should be executed through this. In order to perform rehabilitation training, assistant systems that the aged may rely on are widely used. The assistant systems may easily realize repetitive operations, and support the postures of patients instead, thereby increasing stability and training effects. Actually, the cases in which the rehabilitation using the assistant systems show effects in the upper aim rehabilitation treatments and the neural rehabilitation treatments, and the rehabilitation medical world have interests in treatments using the assistant systems.
An example of such technologies is disclosed in the following patent document and non-patent documents.
For example, Patent Document 1 (Korean Patent No. 10-0623417 (registered on Sep. 6, 2006)) discloses a walking assistant apparatus for old persons and rehabilitation patients including: a lower body having a plurality of legs installed on the left, right, front and rear sides thereof, and a horizontal frame connecting upper ends of the legs while being curved in a channel type a rear side of which is opened; an upper body having at least one pair of vertical frames arranged on the left and right sides and lower ends of which are coupled to opposite ends of the horizontal frame to be detachable from the horizontal frame and such that the heights thereof may be adjusted, and a plurality of connecting frames arranged on the left and right sides and connecting the front sides of the vertical frames corresponding to each other; and a safety fixing member connected to the upper body such that a walker may put on the safety fixing member, wherein the safety fixing member is detachably connected to the upper by four or more fixing members.
Further, Patent document 2 (Korean Unexamined Patent Publication No. 2012-0064571 (published on Jun. 19, 2012)) discloses a walking assistant robot control apparatus including a sensor unit configured to detect an input electromyogram and analyze the detected electromyogram signal, a signal generating unit configured to generates a walking signal according to a change degree of contraction of muscles through the analyzed electromyogram signal, and a control unit configured to control a walking assistant robot by using a walking signal.
Further, because the rehabilitation using a robot shows effective cases in the upper aim rehabilitation treatments and the neural rehabilitation treatments, the rehabilitation medical world having great interests in the treatment using robots. For example, the following non-patent document (J. Perry and J. Burnfield, Gait Analysis: Normal and Pathological Function, 2nd Edition, SLACK Incorporated, 2010.) discloses a technology of designing a controller configured to be operated according to the walking of the user for walking rehabilitation using a robot.
However, in the prior art, because it is difficult to accurately estimate the step length of a walker, it is impossible to drive the walking assistant device according to the walking of the walker. That is, it is important to perform a walking rehabilitation according to the walking of the walker, and according to the related art, it is impossible to control the assistant system according to the walking of the walker.
Further, the estimation of a joint angle of a knee-joint according to the related art includes a method using a pressure sensing resistor (FSR) on the bottom of a foot, a method using an angle or angular speed sensor (an inclination sensor, an acceleration sensor, or a gyro sensor), and a method using a vision system, but it is difficult to estimate a gate phase in a time series scheme.